Search Engine Marketing or SEM is online marketing using paid and unpaid promotional methods to drive traffic to a website via search engines.

SEM involves using search engine optimization (SEO) in order for the website to rank higher for specific keywords in the search engines and bring organic traffic to the website. And it also involves using paid advertising methods like PPC ads on search engines to bring paid traffic to the website.

For a website buyer performing due diligence on a website it is important to understand how a website attracts traffic by carefully studying its traffic reports. A buyer must understand how unpaid SEO and paid search engine advertising are performed.